A stapler for performing binding processing of binding a sheet with a staple, the stapler includes: a driver unit configured to drive the staple to the sheet; a bending unit configured to bend a staple leg of the staple that is driven by the driver unit and penetrates the sheet; a single motor configured to operate the driver unit and the bending unit; a coupling portion coupling the driver unit and the bending unit on one side in a direction orthogonal to a sheet passing direction of the sheet passing between the driver unit and the bending unit and along the sheet surface in the case of performing the binding processing; and a transmission unit configured to transmit a driving force of the motor to at least one of the driver unit or the bending unit via the coupling portion.